模拟移动床色谱分离甘草苷和甘草素

以十八烷基硅烷键合硅胶(ODS)为固定相,V(乙醇)∶V(水)=30∶70为流动相的模拟移动床色谱(SMBC)体系对甘草黄酮中甘草苷与甘草素进行连续分离。SMBC体系设置洗脱带Ⅰ:1根色谱柱;精制带Ⅱ:2根色谱柱;吸附带Ⅲ:2根色谱柱,Ⅰ带独立,Ⅰ带洗脱液为乙醇。按照理想三角形理论选择SMBC操作参数,操作参数包括流动相流速、进料液流速和切换时间。结果表明:接近三角形底边选择SMBC的操作条件,在萃余液出口得到甘草苷,HPLC纯度高于70.44%,收率高于95.17%,同时在萃取液出口得到甘草素,HPLC纯度高于73.10%,收率高于90.74%,SMBC能有效分离甘草苷和甘草素。甘草苷萃余液和甘草素萃取液分别经浓缩、重结晶后,两种产品HPLC纯度均超过96%。     

羟丙基纤维素填充色谱柱的研制及其应用

根据2010版药典要求,研制了20%OV-7 i.d.2 mm×0.5 mm×3 m填充色谱柱用于分析羟丙基纤维素中羟丙氧基含量的分析。考察了色谱柱的规格、不同载体对羟丙基纤维素中被测组分的影响。建立了羟丙基纤维素色谱柱制备及样品定性、定量的新方法。试验结果表明,在选定的色谱条件下,各组分的分离度和理论塔板数都远超药典中规定的参数。标准样品的重复性好,理论塔板数(n),校正因子(RSD),相对标准偏差(RSD%)分别为6,1.41%,0.40%,完全符合药典的检测要求。     

液化气中二甲醚及甲缩醛填充色谱柱的研制及其应用

考察了色谱柱的规格、不同填料对液化气中二甲醚和甲缩醛组分分离的影响。研制出Porapak N i.d.2 mm×0.5 mm×3 m填充色谱柱用于液化气中二甲醚、甲缩醛组分的分析。建立了液化气中二甲醚、甲缩醛色谱柱制备及定性、定量的新方法。试验结果表明,在选定的色谱条件下,标准气体的重复性好,二甲醚和甲缩醛的理论塔板数(n),分离度(r),拖尾因子(t)的相对标准偏差(RSD)分别为1.76%,1.12%;0.91%,1.33%;1.50%,1.21%。各组分的分离度和理论塔板数都能满足日常分析工作的要求。     

新型聚乙烯亚胺型HILIC固定相的制备及其色谱性能研究

制备了一种新型聚合物键合硅胶亲水作用色谱(HILIC)固定相,并利用傅里叶红外分析光谱和元素分析对该固定相进行表征,结果表明,聚合物已成功固定于硅胶表面。在亲水作用色谱模式下,利用经典的核苷类化合物对上述固定相的分离性能进行评测,结果表明,所制备的固定相对核苷类样品表现出较好的分离效果,并且其保留行为符合典型的亲水作用色谱的保留特征;另外,流动相的种类和柱温对上述固定相的保留行为存在较大的影响。     

3微米球型硅胶(GYQG-SiO_2)及其十八烷基化学键合固定相的研制

一、前言化学键合固定相的出现是液相色谱技术的重大突破。以5微米、10微米球型硅胶(或无定型硅胶)为基质,化学键合非极性和极性的多种固定相,柱效高、容量大,各具分离分析特性,使HPLC技术获得了极为迅速的发展与普及。球型硅胶需要特别的合成路线,生产成本较高,但渗透性好,更适用于柱色谱。无定型硅胶的渗透性差,但成本较低,多用于高效簿层色谱。我们研制的微粒硅胶键合相属于上述类型。     

聚合物型反相/离子交换混合模式固定相的制备及应用于β-受体激动剂的分离

采用表面引发的原子转子自由基聚合(SI-ATRP),以硅胶为基质,表面修饰聚(4-乙烯基苯磺酸钠),得到聚合物型反相/离子交换混合模式固定相。考察β-受体激动剂在色谱柱上的保留行为,证明该固定相具有反相和离子交换的双重保留特性。与商品化的反相柱对照,该色谱柱对实际样品猪肝酶解液具有更好的分离度和选择性。结果表明,通过SI-ATRP方法,在硅胶表面构筑聚合物是制备混合模式固定相的一种新方法。     

杜檊氏菌B2的蓝色素成分的分离及化学结构解析

从杜檊氏B2菌体中提取蓝色色素,从中分离得到两中组分（Ⅰ、Ⅱ）,经过高效液相色谱分离纯化,质谱以及核磁共振等分析,确定组分Ⅰ脱氧紫色杆菌素、组分Ⅱ为紫色杆菌素。本研究首次证明杜檊氏菌属也能合成紫色杆菌素。     

HPLC法测定五味子中五味子甲素含量

为测定五味子中五味子甲素含量,采用HPLC法分析检测,色谱柱:Hypersil C18(10μm,250×4.6 mm),流动相:甲醇-水(85∶15),流速:0.6 mL/min,检测波长:254 nm,柱温:25℃。结果表明,五味子中五味子甲素与其他组分良好分离,五味子甲素保留时间约为9.6 min。五味子甲素对照品线性范围0.0025～0.35μg,r=0.99995,平均回收率为100.47%。本法灵敏度高、操作简便、结果准确,可用于五味子中五味子甲素含量的测定。     

超临界流体色谱纯化Z-藁本内酯的研究

将超临界流体色谱技术应用于当归挥发油中Z-藁本内酯的提纯。采用ZorBax SB-C18色谱柱(250 mm×9.4 mm I.D.,5μm),分别考察了改性剂、流速、压力、温度对色谱分离过程的影响,确定了较适宜的色谱提纯条件:CO2流速10 g·min-1,柱温313.15 K,柱压14 MPa;在此工艺条件下提纯制备Z-藁本内酯单体,得到的产品纯度为98.5%(wt)。研究了色谱过程的热力学规律,绘制色谱分离过程的van’t Hoff曲线,并由此得到了色谱相转移过程焓变为21.46kJ·mol-1,并比较了Z-藁本内酯与相邻组分从流动相到固定相分配过程中焓变和熵变的差值,在此条件下Z-藁本内酯色谱分离过程为焓控过程。     

甘草素热转变产物鉴定及转变动力学研究

目的:研究甘草素熔融的转变产物和溶液中的转变产物及其转变动力学。方法:通过硅胶柱层析色谱柱分离转变产物,运用紫外光谱、液质联用、核磁共振波谱等技术,确定甘草素转变产物的结构;通过高效液相色谱法法研究温度和p H对甘草素在溶液中转变动力学的影响。结果:甘草素经过熔融和溶液中的转变产物均是异甘草素。一定时间范围内,溶液中的甘草素向异甘草素的转变与时间成正向的线性关系,转变速率与温度和p H有关。结论:甘草素在制剂和分析过程中应避免高温,其溶液也应避免受热并维持较低的酸性环境。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、环氧树脂、不饱和聚酯树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。